JP4698852B2 - Servo valve cleaning method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for cleaning a servo valve.
[0002]
[Prior art]
Servo valves used in power plant fuel control valves, etc., are usually extracted after an operation confirmation test using an inexpensive mineral hydraulic fluid such as turbine oil. Since then, working phosphate-based hydraulic fluids have been used.
[0003]
[Problems to be solved by the invention]
However, mineral hydraulic oil is prone to thermal degradation, so if it remains in the servo valve, it will generate sludge after a while after actually using the servo valve in a plant or the like. There is a case where the threshold (dead zone) of the servo valve is increased by adhering to the spool and increasing the sliding resistance. For this reason, it is necessary to completely remove the mineral hydraulic oil from the inside of the servo valve after the operation check test of the servo valve. However, conventionally, since the mineral hydraulic fluid is extracted from the servo valve only by its own weight, it takes a very long time to completely remove the mineral hydraulic fluid.
[0004]
In view of the above, an object of the present invention is to provide a servo valve cleaning method capable of reliably removing hydraulic oil for an operation confirmation test from the inside in a short time.
[0005]
[Means for Solving the Problems]
In order to solve the above-described problems, a servo valve cleaning method according to the present invention is a servo valve cleaning method for removing hydraulic oil for operation check tests remaining in a servo valve, An AC current energizing cleaning process for circulating the operating oil or volatile oil for operating the servo valve inside the servo valve while supplying an AC current to the coil; and a current of the servo valve while supplying a DC current to the coil of the servo valve by performing a direct current energization washing step of flowing inside the hydraulic oil or volatile oil for operation of the servo valve, and characterized in that so as to remove the working fluid for operation confirmation test from the interior of the servo valve To do.
[0007]
In the servo valve cleaning method described above, the direct current energization cleaning step is performed after the alternating current energization cleaning step.
[0008]
In the servo valve cleaning method described above, the second AC current energization cleaning step is performed after the DC current energization cleaning step.
[0009]
In the servo valve cleaning method described above, the hydraulic oil for the operation confirmation test is mineral, and the hydraulic oil for operation is a phosphate ester type or a halogenated hydrocarbon type.
Further, the servo valve cleaning method according to the present invention includes an AC current energizing cleaning process in which operating oil or volatile oil is circulated in the servo valve while an AC current is supplied to the servo valve coil, and a DC is applied to the servo valve coil. The inside of the servo valve is cleaned by performing a direct current energization cleaning process in which working oil or volatile oil flows through the servo valve while flowing current.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the servo valve cleaning method according to the present invention will be described below, but the present invention is not limited to these embodiments.
[0011]
[First embodiment]
A first embodiment of a servo valve cleaning method according to the present invention will be described with reference to FIGS. FIG. 1 is a schematic configuration diagram of a servo valve, and FIG. 2 is a schematic configuration diagram of an apparatus used for carrying out a cleaning method.
[0012]
As shown in FIG. 1, when the hydraulic oil 100 is supplied from the supply port 11a of the body 11 of the servo valve 10, the hydraulic oil 100 flows into the inlet orifices 13a and 13b on both sides via the inlet filter 12, and the flow path 14a. , 14b through the nozzles 15a, 15b and into the drain union 16, respectively, and from the outlet 11b.
[0013]
At this time, when a current is passed through the coil 19, the armature 20 swings and the flapper 21 tilts due to the action of the upper magnetic pole 17 and the lower magnetic pole 18. Here, for example, in FIG. 1, when the armature 20 is swung so that the right side of the armature 20 is lowered and the left side is raised, the flapper 21 is swung so that the lower end side approaches the front end side of the left nozzle 15a. While the back pressure of the hydraulic oil 100 ejected from the nozzle 15a increases, the back pressure of the hydraulic oil 100 ejected from the other right nozzle 15b decreases.
[0014]
For this reason, while the pressure in the flow path 14a increases, the pressure in the flow path 14b decreases, so the spool 22 moves to the right in FIG. 1, and the supply port 11a and the port 11d communicate with each other. The hydraulic oil 100 from the port 11a can be sent out from the port 11d, and the discharge port 11b and the port 11c communicate with each other to discharge the hydraulic oil 100 from the port 11c to the discharge port 11b.
[0015]
On the other hand, when the armature 20 is swung so that the right side of the armature 20 is raised and the left side is lowered, the flapper 21 is swung so that the lower end side approaches the front end side of the right nozzle 15b and is ejected from the nozzle 15b. While the back pressure of the oil 100 is increased, the back pressure of the hydraulic oil 100 ejected from the other left nozzle 15a is decreased.
[0016]
For this reason, the pressure in the flow path 14b increases, while the pressure in the flow path 14a decreases, so the spool 22 moves to the left in FIG. 1, and the supply port 11a and the port 11c communicate with each other. The hydraulic oil 100 from the port 11a can be sent out from the port 11c, and the discharge port 11b and the port 11d communicate with each other to discharge the hydraulic oil 100 from the port 11d to the discharge port 11b.
[0017]
In FIG. 1, reference numeral 23 denotes a flexure tube that supports the flapper 20 so as to be swingable, 24 denotes a feedback spring that returns the flapper 20 to a set position, and 25 denotes a sleeve that supports the spool 22 so as to be slidable.
[0018]
In such a servo valve 10, a test for confirming the above-described operation is performed using an inexpensive mineral-based hydraulic oil as an operation confirmation test hydraulic oil, and the hydraulic oil is supplied to the supply port 11 a after the test. Even if it is extracted from the discharge port 11b and the ports 11c and 11d by its own weight, the parts having a small flow cross-sectional area, specifically, the inlet orifices 13a and 13b, the flow paths 14a and 14b, the nozzles 15a and 15b, the drain union 16, etc. The hydraulic oil tends to remain in the part.
[0019]
Next, a method for cleaning the servo valve 10 for removing the mineral-based hydraulic oil for the operation confirmation test that has remained in the above place will be described.
[0020]
As shown in FIG. 2, the port 11 c and the port 11 d of the servo valve 10 are connected by a pipe 1 having a valve 2 in the middle, the pump 4 is operated, and phosphoric acid which is a working hydraulic oil in the tank 3. When the ester-based hydraulic oil 101 is supplied into the servo valve 10 from the supply port 11a of the servo valve 10 and an alternating current is passed through the coil 19 of the servo valve 10 by the function generator 5 and the servo amplifier 6 as an open loop signal (for example, , Sin wave, ± 100% input, 2 Hz, 10 minutes), the armature 20 of the servo valve 10 swings alternately in the left-right direction, the tip side of the flapper 21 swings left and right, and flows out from the nozzles 15a, 15b. Since the back pressure of the phosphate ester hydraulic oil 101 alternates between high and low, the spool 22 slides alternately in the left-right direction, and the ports 11c and 11d are connected to the supply port 11 Phosphate ester hydraulic oil 101 is returned from the switched while the discharge port 11b alternately into the tank 3 to the outlet 11b (the AC current energization washing step). By this operation, in particular, the mineral hydraulic oil remaining in a portion having a small flow cross-sectional area, such as the inlet orifices 13a and 13b, the flow paths 14a and 14b, the nozzles 15a and 15b, the drain union 16 and the like, is phosphate-based. The hydraulic oil 101 can be efficiently cleaned and removed.
[0021]
When such an AC current energization cleaning process is completed, when a DC current is passed through the coil 19 of the servo valve 10 by the function generator 5 and the servo amplifier 6 as an open loop signal (for example, + 100% input for 30 seconds, −100% Input for 30 seconds), the connection described above, the connection between the supply port 11a and the port 11c and the connection between the discharge port 11b and the port 11d, or the connection between the supply port 11a and the port 11d, and the discharge port 11b and the port 11c. Are connected to each other for a predetermined time (30 seconds) (DC current energization cleaning step). By this operation, in particular, the mineral-based hydraulic oil remaining in a relatively large portion of the flow cross-sectional area communicating with the supply port 11a, the discharge port 11b, and the ports 11c, 11d is more efficiently produced by the phosphate ester-based hydraulic oil 101. Can be washed and removed well.
[0022]
Therefore, according to such a cleaning method, the hydraulic oil for the operation check test can be reliably removed from the inside of the servo valve 10 in a short time.
[0023]
In the present embodiment, the direct current energization cleaning process is performed after the alternating current energization cleaning process is performed. However, the alternating current energization cleaning process can be performed after the direct current energization cleaning process is performed. . However, if the direct current energization cleaning process is performed after performing the alternating current energization cleaning process as in the present embodiment, a portion with a small flow cross-sectional area where the hydraulic oil for the operation check test is likely to remain can be obtained. Since it can wash | clean efficiently previously and cleaning efficiency can be raised more, it is preferable.
[0024]
[Second embodiment]
A second embodiment of the servo valve cleaning method according to the present invention will be described with reference to FIG. FIG. 3 is a schematic configuration diagram of an apparatus used for carrying out the cleaning method. However, the same members as those in the first embodiment described above are denoted by the same reference numerals as those used in the description of the first embodiment, and the description thereof is omitted.
[0025]
As shown in FIG. 2, the present embodiment relates to a case where the servo valve 10 attached to the servo actuator 30 that operates the fuel control valve 40 of the fuel 110 of the power plant is cleaned. At this time, the servo actuator 30 connects one port 11d of the servo valve 10 to the corresponding side of the cylinder 31 so that the rod 33 side (tip side) connected to the fuel control valve 40 of the plunger 32 is hydraulically biased. On the other hand, the other side of the plunger 32 is always biased by a biasing means 34 such as a compression coil spring. For this reason, the other port 11c of the servo valve 10 is closed.
[0026]
In such a servo valve 10, after the AC current energization cleaning process is performed in the same manner as in the first embodiment described above, the direct current energization cleaning process is performed, so that the mineral remaining inside The system hydraulic oil can be reliably removed by washing.
[0027]
Further, when an alternating current is passed as a closed loop signal to the coil 19 of the servo valve 10 by the function generator 5 and the servo amplifier 6 while detecting a signal from the position detector 7 of the rod 33 of the servo actuator 30 (for example, sin wave) , ± 100% stroke input), a sufficient amount of phosphate ester hydraulic oil 101 flows into and out of the cylinder 31 of the servo actuator 30, so that the mineral remaining in the cylinder 31 of the servo actuator 30 remains. The system hydraulic oil can also be efficiently cleaned and removed by the phosphate ester type hydraulic oil 101 (second alternating current energization cleaning process).
[0028]
That is, in the present embodiment, in order to clean the interior of the servo actuator 30 connected to the servo valve 10 with certainty, the second alternating current energization cleaning process is further performed.
[0029]
Therefore, according to the present embodiment, as in the case of the first embodiment described above, the mineral hydraulic oil remaining in the servo valve 10 can be reliably washed and removed. Of course, the mineral hydraulic oil remaining in the cylinder 31 of the servo actuator 30 can also be reliably removed.
[0030]
In this embodiment, the second AC current cleaning process is performed after the AC current cleaning process and the DC current cleaning process, but the order of these cleaning processes is changed. Even in this case, it is possible to clean the inside of the servo valve 10 and the servo actuator 30. However, if the AC current energization cleaning process is performed and the DC current energization cleaning process is performed after the AC current energization cleaning process is performed as in the present embodiment, the operation for the operation confirmation test is performed. Since it can wash | clean efficiently from the location where oil remains easily, it is preferable from the fact that washing efficiency can be improved more.
[0031]
In the present embodiment, the case where the servo valve 10 attached to the servo actuator 30 that operates the fuel control valve 40 of the power plant is cleaned has been described. However, the present invention is not limited to this, and the control valve of other equipment is operated. When cleaning the servo valve attached to the servo actuator to be cleaned, as well as when cleaning the servo valve connected to various hydraulic devices, it can be cleaned in the same manner as in this embodiment. .
[0032]
Further, in each of the above-described embodiments, a phosphate ester type oil is used as an operating hydraulic oil. However, even when a halogenated hydrocarbon type oil is used, It can be applied in the same way.
[0033]
Further, in each of the above-described embodiments, the working hydraulic fluid is used to remove the hydraulic fluid for the operation confirmation test. Instead, for example, volatile oil such as gasoline, benzine, or thinner is used. It is also possible to use it. Here, when cleaning is performed in the same manner as in each of the above-described embodiments using volatile oil, the volatile oil is discharged from the servo valve, and then the servo valve is evacuated while reducing the pressure with a vacuum pump or the like. The volatile oil in the servo valve can be easily removed in a short time to such an extent that there is almost no problem.
[0034]
【The invention's effect】
A cleaning method for a servo valve according to the present invention is a cleaning method for a servo valve that removes hydraulic fluid for an operation confirmation test remaining in the servo valve, and the servo valve is caused to flow while an alternating current is applied to the coil of the servo valve. AC current energizing cleaning process for circulating the working fluid or volatile oil for operating the servo valve inside the valve, and operating the servo valve inside the servo valve while flowing a direct current through the coil of the servo valve. by performing a direct current energization washing step for circulating the hydraulic oil or volatile oil. Thus remove hydraulic fluid for operation confirmation test from the interior of the servo valve, the servo valve the hydraulic oil for operation confirmation test it is possible to reliably removed in a short time from the inside, a small portion and a relatively large working fluid for operation confirmation test remaining in place of the cross-sectional flow area of the flow cross-sectional area which Re can be efficiently washed away.
[0036]
In addition, since the direct current energization washing process is performed after the alternating current energization washing process, the hydraulic oil for the operation confirmation test remaining in the small portion of the flow cross-sectional area and after the washing is efficiently removed first, It is possible to efficiently wash and remove the hydraulic oil for the operation confirmation test remaining in a portion having a relatively large flow cross-sectional area. For this reason, the inside of the servo valve can be cleaned and removed more efficiently.
[0037]
In addition, since the second AC current energization cleaning process is performed after the DC current energization cleaning process, when cleaning the servo valve connected to the hydraulic equipment, the hydraulic equipment should be cleaned and removed more efficiently. Can do.
[0038]
In addition, since the hydraulic oil for the operation confirmation test is mineral and the hydraulic fluid for operation is a phosphate ester type or a halogenated hydrocarbon type, the above-described effects can be particularly expressed.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a servo valve.
FIG. 2 is a schematic configuration diagram of a first embodiment of an apparatus used for carrying out a servo valve cleaning method according to the present invention;
FIG. 3 is a schematic configuration diagram of a second embodiment of an apparatus used for carrying out a servo valve cleaning method according to the present invention.
[Explanation of symbols]
1 Piping 2 Valve 3 Tank 4 Pump 5 Function generator 6 Servo amplifier 7 Position detector 10 Servo valve 11 Body 11a Supply port 11b Discharge port 11c, 11d Port 12 Inlet filters 13a, 13b Inlet orifices 14a, 14b Flow paths 15a, 15b Nozzle 16 Drain union 17 Upper electrode 18 Lower electrode 19 Coil 20 Amateur 21 Flapper 22 Spool 23 Flexure tube 24 Feedback spring 25 Sleeve 30 Servo actuator 31 Cylinder 32 Plunger 33 Rod 34 Energizing means 100 Hydraulic oil 101 Phosphate ester hydraulic oil

Claims (5)

A method of cleaning a servo valve that removes hydraulic fluid for operation confirmation test remaining inside the servo valve,
AC current energizing cleaning step of circulating working oil or volatile oil for operating the servo valve in the servo valve while flowing an alternating current through the coil of the servo valve;
A DC current energizing cleaning step of flowing a working oil or volatile oil for operating the servo valve inside the servo valve while flowing a direct current through the coil of the servo valve;
The servo valve cleaning method is characterized in that the hydraulic fluid for the operation confirmation test is removed from the inside of the servo valve by performing the above . In claim 1 ,
A servo valve cleaning method, wherein a DC current energization cleaning process is performed after an AC current energization cleaning process. In claim 2 ,
A servo valve cleaning method, comprising: performing a second alternating current energization cleaning step after performing the direct current energization cleaning step. In any one of Claim 1 to 3 ,
The hydraulic oil for the operation confirmation test is mineral,
A method for cleaning a servo valve, wherein the operating hydraulic fluid is a phosphate ester type or a halogenated hydrocarbon type. AC current electrification washing process in which working oil or volatile oil is circulated inside the servo valve while passing an alternating current through the coil of the servo valve;
A direct current electrification washing step for flowing hydraulic oil or volatile oil inside the servo valve while flowing direct current through the coil of the servo valve;
The servo valve cleaning method is characterized in that the inside of the servo valve is cleaned by performing

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